Abstract

When rare documents are collected and reprinted as Opere, Oeuvres, and Gesammelte Schriften, new diagrams are introduced. For the most part the new are faithful reproductions of the old. Sometimes, however, editors correct or simplify diagrams. Thus, before one writes, “so-and-so represents the area to be squared by seven parallelograms,” the more meticulous among us make a before-and-after comparison to insure that the “So-and-so” dividing the space is in fact the mathematician under scrutiny, and not some subsequent draftsman. This underlines the importance of the facsimile edition.